Table 9.

Effects of nitrogen deficiency and compensation on N absorption and utilization efficiency of double-cropping super hybrid late rice in 2015.

Treatments	RENa (%)	AENb (kg kg-1)	PENc (kg kg-1)	PFPNd (kg kg-1)	HINe (%)
CK0	0	0	0	0	74.80b
CK1	52.30a	22.50a	43.25a	38.74a	78.10a
CK2	52.00a	23.15a	44.15a	43.38a	77.60a
T1	56.10a	24.53a	43.69a	40.78a	77.00a

CK0, N fertilizer was not supplied during all stages of growth (blank control); CK1, constant supply of N throughout different stages of growth; CK2, constant N compensation at young panicle differentiation stage, after N deficiency at tillering stage; T1, double N compensation at young panicle differentiation stage, after N deficiency at tillering stage. In 2015, values in the same column show means via the Tukey’s multiple range test, and different letters indicate that the means were statistically different (P < 0.05), n = 4. ^aHI_N, N harvest index = (N in grains)/(total N absorption in plant) × 100%. ^bRE_N, N recovery efficiency = (total above ground plant N accumulation in the plot that received N fertilizer–total above ground plant N accumulation in the zero-N control)/(amount of N fertilizer applied) × 100%. ^cAE_N, N agronomic efficiency = (Grain yield in the plot that received N fertilizer–grain yield in the zero-N control)/(amount of N fertilizer applied). ^dPE_N, N physiological efficiency = (Grain yield in the plot that received N fertilizer–grain yield in the zero-N control)/(total above ground plant N accumulation in the plot received N fertilizer–total above ground plant N accumulation in the zero-N control). ^ePFP_N, N partial factor productivity = (Grain yield in the plot that received N fertilizer)/(amount of N fertilizer applied; Data are averages observed for the study year of 2015) (n = 3, 1 year × 3 replicates).